With a trivial Golang-built program loaded in gdb-7.8.90.20150214-7.fc23.x86_64
I get this error:

(gdb) source ./src/runtime/runtime-gdb.py
Loading Go Runtime support.
Traceback (most recent call last):
  File "./src/runtime/runtime-gdb.py", line 230, in <module>
    _rctp_type = gdb.lookup_type("struct reflect.rtype").pointer()
gdb.error: No struct type named reflect.rtype.
(gdb) q

No matter if this struct should or should not be in every Golang-built binary
this change should fix that with no disadvantages.

Change-Id: I0c490d3c9bbe93c65a2183b41bfbdc0c0f405bd1
Reviewed-on: https://go-review.googlesource.com/5521Reviewed-by: Ian Lance Taylor <iant@golang.org>